DESCRIPTION: (provided by the applicant): It is evident that Africa has great need to produce more food for its inhabitants. It is also evident that large irrigation projects, such as occur on the Niger River, can make otherwise and land much more productive, thereby bettering the lives of those nearby. However, at the same time that irrigation increases agricultural yield from the land, it also provides breeding sites for parasites and that may greatly exacerbate problems like malaria and schistosomiasis. Our goal is to develop mathematical models and simulation tools to explain why large irrigation projects usually increase malaria transmission, but sometimes do not, and sometimes even decrease transmission, as in the region around Niono, a Niger River irrigation project in Mali. The global behavior of mosquito populations is complex. Computer simulations suggest that much of this complexity results from the collective behavior of large numbers of interacting factors, which are not so complex individually. We will look at data from several disciplines to measure or extract the required parameters from samples of mosquitoes and humans, and use remote sensing to expand the predictions to a larger area. We will use a series of predict-test-refine cycles to develop and validate the model. Finally, we shall ask a series of aboutWhat if questions to explore alternatives and identify those operations most likely to increase or ameliorate malaria problems associated with irrigation. Consultants to the Niono irrigation district managers (Office du Niger) and Malian Malaria Control Agency are collaborators with this project, ensuring that the model will find immediate practical application.